The tetrahedral voids formed by $ccp$ arrangement of $Cl^{-}$ ions in rock salt structure are

$A$ compound is formed by elements $A$ and $B$. This crystallizes in a cubic structure where atoms $A$ are at the corners of the cube and atoms $B$ are at the body center. The simplest formula of the compound is:

Which of the following statements is incorrect?

For an ionic crystal of the type $AB$,the value of the limiting radius ratio is $0.40$. This value suggests that the crystal structure should be:

$A$ solid $A^{+}B^{-}$ has a $NaCl$ type close-packed structure. If the radius of the anion is $250 \ pm$, what should be the ideal radius of the cation in $pm$?

In a face centered cubic lattice,atoms $A$ are at the corner points and atoms $B$ are at the face centered points. If one atom $B$ is missing from one of the face centered points,the formula of the ionic compound is: